The present invention relates to a drain device for the removal of condensate from systems under pressure. For example, in a gas dehydration system, the system is under a continuous steady pressure and the gas is dehydrated continuously by means of a process such as a pressure swing adsorption process or a membrane process or the like. In a continuous process under pressure, any significant deviation in the pressure reduces the efficiency of the process by a multiple factor. Thus in the dehydration of a gas under pressure, moisture should be removed on a continuous basis without a significant reduction in the pressure of the system or without interruption of the continuous flow.
Many devices have been developed to drain condensate from systems used for dehydration of a gas. Most generally these devices require interruption of the process entirely or a variation in the system pressure which substantially reduces the efficiency of the system.
U.S. Pat. Nos. 4,116,650 and 4,400,187 to Arlo E. Lane disclose a device for eliminating droplets of water from a stream of compressed air in which the air is passed through a plug of porous water absorbent material which absorbs the droplets. Continued passage of the air through the plug evaporates the water from the plug. In this situation, compressed air is needed to effect the evaporation.
U.S. Pat. No. 4,345,767 to Brian P. Neal utilizes the action of a piston which is deflected upwardly to permit ejection of moisture through an aperture into which the piston fits. This device requires the system pressure be interrupted during ejection of water.
U.S. Pat. No. 4,874,408 to Kenneth W. Overby features a drain which is an enclosed bowl suspended beneath a sump, and an aspiration tube which extends from within the bowl such that air circulated into the bowl causes the liquid to be aspirated through the tube. This device requires a change in pressure to aspirate the liquid.
In continuous gas systems, such as dehydration of gas, the moisture is ordinarily condensed upon the moisture leaving the primary dehydration stream. Upon condensation it is desirable to remove the liquid from the system continuously.
The present invention provides a device for continuously removing liquid condensate from continuous systems under pressure without significant lowering of the pressure or interruption of the system.